Like many racers in pursuit of the land-speed record, Frank Lockhart had talent, nerves of steel, and boundless determination. Also like many racers in pursuit of the land-speed record, Frank Lockhart died in that pursuit, leaving behind many unanswered questions, including that of what exactly caused the fatal crash, and could it have been something so innocuous as a seashell?

Lockhart burst onto the international racing scene in May 1926 when, as a rookie, he won that year’s rain-shortened Indianapolis 500 driving a supercharged eight-cylinder Miller and placed second in the year’s overall standings. His racing career, however, began about three years earlier in California, where he raced on board tracks, dirt tracks, and the dry lakes. On the latter, he reportedly recorded speeds of up to 171 MPH, which in 1926 would have put him in contention with then-current world land-speed record holders.

His win at Indy not only convinced Fred Moscovics, then president of Stutz, that Lockhart was “in my opinion, the greatest automobile racing driver who ever lived,” it also convinced Moscovics to hire Lockhart to assemble a racing team that would promote the new Stutzes, nicknamed the “Safety Stutz.” Introduced in 1926, the Stutz Series AA boasted a number of safety features, including wire-reinforced safety glass, four-wheel hydraulic brakes, steel running boards riveted to the frame to serve as side bumpers, and a lower center of gravity made possible by a worm gear rear axle.

Safety and speed were not mutually exclusive at that time, however: In addition to the safety features, the new Stutzes also received more powerful single-overhead-camshaft straight-eight engines, which Stutz tested at the Indianapolis Motor Speedway and which Lockhart was tasked with campaigning in motorsports. Stutz sales literature claimed top speeds for its models of up to 80 MPH.

Lockhart, as many a biography of him notes, was skilled not just as a driver but also as a mechanic and engineer, and he lent his talents to Stutz’s engineering department in an effort to wring better performance out of the Safety Stutzes. At the same time, with his dry lakes experience still fresh in his mind, Lockhart seized the opportunity to have Stutz sponsor a run at the world land-speed record. In late 1927, Moscovics furnished him a space in Stutz’s shops and a team of builders and engineers that included Floyd “Pop” Dreyer.

While many of the land-speed record cars of the time tended toward the massive end of the scale, Lockhart believed smaller, lighter, and more aerodynamic cars had a better chance at setting speed records. After all, he made his 171 MPH run in a car powered by a supercharged and intercooled 91-cu.in. Miller.

Thus, his land-speed car would have almost nothing in common with a production Stutz. To power it, he lashed together a pair of Miller 91-cubic-inch double overhead-camshaft eight-cylinder engines in a 30-degree V-16 configuration on a common crankcase with each bank of cylinders turning its own crankshaft. In addition to supercharging the engine, Lockhart intercooled it and placed the intercoolers atop the hood to avoid interrupting airflow. Just about everything else Lockhart enclosed, and what he couldn’t enclose he shaped to cheat the wind. Lockhart and his team aimed for 225 MPH out of the 2,800-pound car.

In February 1928 Lockhart took his Stutz Black Hawk Special to Daytona Beach, where Henry Segrave had set the land-speed record less than a year prior at 203 MPH, and where Malcolm Campbell had upped it just a few days earlier to 206 MPH, using his 1,464-cubic-inch Bluebird. Lockhart, according to historian John Bayer, managed runs of 180 MPH, faster than he’d run before, but not fast enough. Then, after a storm roughed up the beach, the uneven sand (or, according to some sources, a surprise squall) sent Lockhart and the Black Hawk Special into the surf at about 200 MPH. Lockhart was bruised, concussed, and suffered cut tendons. The car was mangled but repairable.

Moscovics reportedly wanted Lockhart to wait until the following year to make another attempt at the record, but Lockhart pushed to have the car repaired within two months, probably because Ray Keech used those weeks to again re-set the record in his 5,000-plus cubic inch White Triplex, this time to 207 MPH. Lockhart decided to make his attempt on April 25.

His first run down the beach only just cleared 203 MPH, but Lockhart reportedly believed the Black Hawk Special could go fast enough on the return run to bring the two-way average up above Keech’s speed. Indeed, he reportedly hit 220 MPH before something caused the car to start tumbling down the beach, throwing Lockhart to his death.

Bayer wrote that “when officials examined the course and the marks the car made, they found a clam shell in the skid left at the end of his last practice, evidence the shell had sliced the tire.” Indeed, at that speed any foreign object could cause considerable damage. However, of the numerous crashes that occurred during land-speed racing attempts on beaches, Lockhart’s stands out as the only one attributed to a sea shell.

Other theories have been floated. As Gordon Buehrig, who designed cars at Stutz in the late Twenties, reportedly told the tale, the skidding that took place before the car upended resulted from a worm-drive rear axle that locked up after Lockhart ran out of fuel and the engine died. Because Moscovics had touted the worm-drive rear axle as one of the Safety Stutz’s significant safety features — and because he didn’t want it to take the blame for Lockhart’s death — Buehrig asserted that Moscovics arranged to shift the blame for the crash to a blown tire caused by a seashell.

Nor should Lockhart’s injuries from the previous crash be overlooked. Despite advances in sports medicine, concussions and torn tendons still take athletes out of their games for weeks at a time; Lockhart, despite his young age, was likely far from peak physical condition at the time of the fatal crash. And a number of people have pointed to a controversy over exactly which tires Lockhart used on his record runs; Firestone reportedly had offered tires designed for those speeds, but Dickinson reportedly offered Lockhart and Stutz more sponsorship money.

Whatever the cause, Moscovics called a halt to all Stutz racing activities immediately after the crash. The engine from the Black Hawk Special was salvaged and continued racing until 1946; today, it resides in the Sampson Special in the Indianapolis Motor Speedway Museum. A replica of the Black Hawk Special, commissioned by Jim Lattin, debuted several years ago. And Lockhart has since been inducted into the Motorsports Hall of Fame of America, his death almost universally described as one of the more tragic in motorsports.